When I had to pay for it myself, I had eFax, and loved it. Its so easy to use... sending and receiving faxes was always a breeze. Now the company I work for has some integrated telephone number/fax thing so we just get them in our emails anyway. I can't send faxes anymore electronically but we have printers in our buildings we can print to and select "fax" in the settings and they send the faxes for us... is a little tricky to figure out but it works okay. I'd definitely choose eFax again if I didn't have my company resources.

Speaking of which, it always surprises me these days when I have to send a fax somewhere. I really prefer just emailing over a PDF of whatever it is. Companies who require faxes these days just strike me as very backward technologically. If its a choice somebody prefers, I understand a company offering it as a channel, but its a little irritating when a fax is required.